a. Field of the Invention
The present invention relates to a lens mount for a microscope objective.
B. Description of the Prior Art
Generally, a microscope is provided with a plural number of objectives respectively different in magnification. When exchanging the objective to be used for observation, a revolver is revolved by holding one of objectives. Usually, the observer touches the objective only when he revolves the revolver.
Recently, however, extremely precise observation and measurement are required for scientific researches in the field of medical science and, consequently, deterioration of the image obtained by the microscope objective caused by the influence of variation in thickness of the cover glass has come into question though such deterioration of the image was neglected in the past. Now, it is therefore required to take some countermeasure to prevent such deterioration of the image caused by variation in thickness of the cover glass and to materialize a means for such countermeasure. To meet this requirement, a microscope objective arranged as follows has been developed. That is, said microscope objective is arranged to move a part of lenses constituting the lens system along the optical axis and to thereby correct or prevent said deterioration of the image caused by the above-mentioned variation in thickness of the cover glass. For the microscope objective having such lens system, it is necessary to provide a correcting mechanism for moving a part of lenses to the lens mount of the objective and to move said part of lenses by rotating a correcting ring which constitutes said correcting mechanism and is arranged on the outer surface of the lens mount.
On microscopes, however, many objectives respectively different in magnification are mounted to the revolver and, therefore, spaces between respective objectives are very small and are not sufficient to insert the observer's fingers therein. When microscope objectives having the above-mentioned correcting mechanism are mounted to such revolver, it is very difficult to rotate said correcting ring by holding said correcting ring by fingers. Moreover, as the diameter of the lens mount of the objective cannot be made large, it is necessary to make the thickness of the correcting ring as small as possible. When, therefore, such thin correcting ring is held by fingers in order to rotate it, the correcting ring will be deformed and it will become impossible to rotate the correcting ring smoothly.
To solve the above problem, it may be possible to rotate the correcting ring by rubbing the surface of the correcting ring by a finger bulb. In that case, however, a correcting ring having knurled outer surface is unsatisfactory because fingers will slip when rotating the correcting ring by rubbing said knurled surface by a finger bulb and the correcting ring cannot be rotated smoothly.